SMT Integer Performance With SPEC CPU2006

Next, to test the performance impact of simultaneous multithreading (SMT) on a single core, we test with two threads on the same core. This way we can evaluate how well the core handles SMT. 

Subtest Application type Xeon E5-2690 @ 3.8 Xeon E5-2690 v3 @ 3.5 Xeon E5-2699 v4 @ 3.6 EPYC 7601 @3.2 Xeon 8176 @ 3.8
400.perlbench Spam filter 39.8 43.9 47.2 40.6 55.2
401.bzip2 Compression 32.6 32.3 32.8 33.9 34.8
403.gcc Compiling 40.7 43.8 32.5 41.6 32.1
429.mcf Vehicle scheduling 44.7 51.3 55.8 44.2 56.6
445.gobmk Game AI 36.6 35.9 38.1 36.4 39.4
456.hmmer Protein seq. analyses 32.5 34.1 40.9 34.9 44.3
458.sjeng Chess 36.4 36.9 39.5 36 41.9
462.libquantum Quantum sim 75 73.4 89 89.2 91.7
464.h264ref Video encoding 52.4 58.2 58.5 56.1 75.3
471.omnetpp Network sim 25.4 30.4 48.5 26.6 42.1
473.astar Pathfinding 31.4 33.6 36.6 29 37.5
483.xalancbmk XML processing 43.7 53.7 78.2 37.8 78

Now on a percentage basis versus the single-threaded results, so that we can see how much performance we gained from enabling SMT:

Subtest Application type Xeon E5-2699 v4 @ 3.6 EPYC 7601 @3.2 Xeon 8176 @ 3.8
400.perlbench Spam filter 109% 131% 110%
401.bzip2 Compression 137% 141% 128%
403.gcc Compiling 137% 119% 131%
429.mcf Vehicle scheduling 125% 110% 131%
445.gobmk Game AI 125% 150% 127%
456.hmmer Protein seq. analyses 127% 125% 125%
458.sjeng Chess 120% 151% 125%
462.libquantum Quantum sim 91% 129% 90%
464.h264ref Video encoding 101% 112% 112%
471.omnetpp Network sim 109% 116% 103%
473.astar Pathfinding 140% 149% 137%
483.xalancbmk XML processing 120% 107% 116%

On average, both Xeons pick up about 20% due to SMT (Hyperthreading). The EPYC 7601 improved by even more: it gets a 28% boost on average. There are many possible explanations for this, but two are the most likely. In the situation where AMD's single threaded IPC is very low because it is waiting on the high latency of a further away L3-cache (>8 MB), a second thread makes sure that the CPU resources can be put to better use (like compression, the network sim). Secondly, we saw that AMD core is capable of extracting more memory bandwidth in lightly threaded scenarios. This might help in the benchmarks that stress the DRAM (like video encoding, quantum sim). 

Nevertheless, kudos to the AMD engineers. Their first SMT implementation is very well done and offers a tangible throughput increase. 

Single Threaded Integer Performance: SPEC CPU2006 Multi-core SPEC CPU2006
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  • ddriver - Wednesday, July 12, 2017 - link

    LOL, buthurt intel fanboy claims that the only unbiased benchmark in the review is THE MOST biased benchmark in the review, the one that was done entirely for the puprpose to help intel save face.

    Because if many core servers running 128 gigs of ram are primarily used to run 16 megabyte databases in the real world. That's right!
  • Beany2013 - Tuesday, July 11, 2017 - link

    Sure, test against Ubuntu 17.04 if you only plan to have your server running till January. When it goes end of life. That's not a joke - non LTS Ubuntu released get nine months patches and that's it.

    https://wiki.ubuntu.com/Releases

    16.04 is supported till 2021, it's what will be used in production by people who actually *buy* and *use* servers and as such it's a perfectly representative benchmark for people like me who are looking at dropping six figures on this level of hardware soon and want to see how it performs on...goodness, realistic workloads.
  • rahvin - Wednesday, July 12, 2017 - link

    This is a silly argument. No one running these is going to be running bleeding edge software, compiling special kernels or putting optimizing compiler flags on anything. Enterprise runs on stable verified software and OS's. Your typical Enterprise Linux install is similar to RHEL 6 or 7 or it's variants (some are still running RHEL 5 with a 2.6 kernel!). Both RHEL6 and 7 have kernels that are 5+ years old and if you go with 6 it's closer to 10 year old.

    Enterprises don't run bleeding edge software or compile with aggressive flags, these things create regressions and difficult to trace bugs that cost time and lots of money. Your average enterprise is going to care about one thing, that's performance/watt running something like a LAMP stack or database on a standard vanilla distribution like RHEL. Any large enterprise is going to take a review like this and use it as data point when they buy a server and put a standard image on it and test their own workloads perf/watt.

    Some of the enterprises who are more fault tolerant might run something as bleeding edge as an Ubuntu Server LTS release. This review is a fair review for the expected audience, yes every writer has a little bias but I'd dare you to find it in this article, because the fanboi's on both sides are complaining that indicates how fair the review is.
  • jjj - Tuesday, July 11, 2017 - link

    Do remember that the future is chiplets, even for Intel.
    The 2 are approaching that a bit differently as AMD had more cost constrains so they went with a 4 cores CCX that can be reused in many different prods.

    Highly doubt that AMD ever goes back to a very large die and it's not like Intel could do a monolithic 48 cores on 10nm this year or even next year and that would be even harder in a competitive market. Sure if they had a Cortex A75 like core and a lot less cache, that's another matter but they are so far behind in perf/mm2 that it's hard to even imagine that they can ever be that efficient.
  • coder543 - Tuesday, July 11, 2017 - link

    Never heard the term "chiplet" before. I think AMD has adequately demonstrated the advantages (much higher yield -> lower cost, more than adequate performance), but I haven't heard Intel ever announce that they're planning to do this approach. After the embarrassment that they're experiencing now, maybe they will.
  • Ian Cutress - Tuesday, July 11, 2017 - link

    Look up Intel's EMIB. It's an obvious future for that route to take as process nodes get smaller.
  • Threska - Saturday, July 22, 2017 - link

    We may see their interposer (like used with their GPUs) technology being used.
  • jeffsci - Tuesday, July 11, 2017 - link

    Benchmarking NAMD with pre-compiled binaries is pretty silly. If you can't figure out how to compile it for each every processor of interest, you shouldn't be benchmarking it.
  • CajunArson - Tuesday, July 11, 2017 - link

    On top of all that, they couldn't even be bothered to download and install a (completely free) vanilla version that was released this year. Their version of NAMD 2.10 is from *2014*!

    http://www.ks.uiuc.edu/Development/Download/downlo...
  • tamalero - Tuesday, July 11, 2017 - link

    Do high level servers update their versions constantly?
    I know that most of the critical stuff, only patch serious vulnerabilities and not update constantly to newer things just because they are available.

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